Protein Information

Releases the supercoiling and torsional tension of DNA introduced during the DNA replication and transcription by transiently cleaving and rejoining one strand of the DNA duplex. Introduces a single-strand break via transesterification at a target site in duplex DNA. The scissile phosphodiester is attacked by the catalytic tyrosine of the enzyme, resulting in the formation of a DNA-(3'-phosphotyrosyl)-enzyme intermediate and the expulsion of a 5'-OH DNA strand. The free DNA strand than undergoes passage around the unbroken strand thus removing DNA supercoils. Finally, in the religation step, the DNA 5'-OH attacks the covalent intermediate to expel the active-site tyrosine and restore the DNA phosphodiester backbone (By similarity). Regulates the alternative splicing of tissue factor (F3) pre-mRNA in endothelial cells.

Topoisomerases regulate the topological states of DNA. Though no direct interaction has been reported, TOP1 has been indirectly linked to WRN [ 14612507]. TOP1 may also be important in the regulation of various brain functions and its activity is age-dependent [ 16261531]. Because TOP1 has been associated with several DNA metabolism proteins thought to play a role in ageing, it is possible that TOP1 is itself involved in human ageing, though further studies are necessary to confirm this hypothesis.

References

MeSH Terms:
Only a subset of the Medical Subject Headings terms is shown: the Major Topics MeSH terms.
They describe one of the main topics discussed in the article denoted by an asterisk on the MeSH term or MeSH/Subheading combination on the PubMed page.
MeSH terms that belong to the Ageing MeSH are highlighted in green.